* China data send Canadian, Aussie dollars lower
* Euro holding most of last week's gains vs dollar
* Ukraine tensions weighing
LONDON, March 10 (Reuters) - The Australian and Canadian dollars lost as much as half a percent against their U.S. counterpart on Monday as a plunge in exports from China underlined the risks of more weakness in one of the big drivers of world growth.
The Aussie had been on the way back up towards the end of last week, boosted by signs of improvement in its own economy. But like fellow commodity producer Canada, it depends on China extending a decade of robust expansion.
More and more doubts are emerging on that front.
Latest numbers showed Chinese exports fell 18 percent year-on-year in February, and authorities in Beijing continued a campaign to halt any further appreciation of the yuan by setting its daily guidance for the currency at the highest since mid-December.
Added to geopolitical risks like a crisis in Ukrainian-Russian relations that looks set to drag on, that left markets in "risk-off" mode, benefitting traditional safe haven currencies like the yen and Swiss franc.
"The Chinese export numbers are the main driver this morning - you can see that the Aussie and Canadian dollars are both under pressure," said Alvin Tann, strategist with French bank Societe Generale in London.
"The situation in Ukraine is back on people's minds and one could already see the pressure on emerging markets on Friday after (strong) U.S. non-farm payrolls."
The Aussie traded 0.4 percent lower in early European trade at $0.9033 and 93.26 yen, having dipped as low as 92.90.
For the big three currencies, that left the yen up around 0.2 percent against both the euro and dollar. The latter pair were stuck close to levels seen at the end of U.S. trading on Friday.
The lack of action - or any sign it is imminent - from the European Central Bank to ease policy further and boost growth drove the euro to a 2 1/2-year high on Friday, only minimally offset by a boost for the dollar from the U.S. jobs data.
The euro inched up about 0.1 percent against the dollar to $1.3886, having peaked at $1.3915 on Friday.
Japan posted a record current account deficit in January on Monday, and its fourth-quarter growth was revised down.
Still, the Bank of Japan is expected to keep policy unchanged at a two-day meeting that began on Monday. Consumer prices remain on track to meet the central bank's 2 percent inflation target.
Analysts cautioned against reading too much into the China trade figures, which may have been distorted by the Lunar New Year holiday, but investors were taking no chances.
The Aussie's robust showing in the past month surprised many who expected it to weaken on the back of poor Chinese numbers. Citigroup analysts argued in a morning note that the Australian economy and currency may be driven more by domestic developments going forward.
"While there is little doubt that a sustained downtrend in Chinese imports would be negative for AUD, there looks to be some cause for caution in overreacting to this weekend's data," they said.
"The relationship between AUD and Chinese economic data flow has deteriorated in recent months, with AUD failing to participate in the stabilization seen in data flow over the second half of 2013."